What are the chances of the new Spanish government of Pedro Sanchez still being in power by Christmas? I would say that the chances are slim. Sanchez only has a small number of members of parliament and is without a majority. He needs the support of other smaller parties to get key legislation through parliament and if this is not forthcoming then he has serious problems.
Sanchez should have secured the support of one of the other main parties before he ventured into the unknown. There was little or no chance of a pact with the centre-right Partido Popular, who were ejected from office by Sanchez, but he could have entered into a pact with one of the other smaller parties, Ciudadanos or Podemos. With such little support it does appear that his government is doomed and I suspect that an election will be called before the end of the year. If Sanchez does fall, I do not think that anyone will be too surprised; after all, he is rather an accidental prime minister.
To stay in power, Sanchez needs support and the Partido Popular is not going to make his life easy, especially when they hold him responsible for ejecting Mariano Rajoy from power. Once the summer break is over and politicians return to their desks, I think we will see Sanchez going from one crisis to another. He can't remain in office unless he gets support, and I doubt that support will be forthcoming.